Mamedzuta - Mamedzuta

An evergreen fern of the Polypodiaceae family. Also called rock bean or legume. The rhizome is long and slender, with sparse scales. The scales are latticed, dark brown, and membranous. The leaves are fleshy, thick, and somewhat glossy, and there are two types: vegetative leaves and sporophyll leaves. Vegetative leaves are round or elliptical, 1-2 cm long, and have short stalks. Sporophyll leaves are spatula-shaped, 2-5 cm long, and have long stalks. Sporangia grow in a line along the midrib, but cover the entire underside when mature. It is distributed from the southern Tohoku region westward, and is common in warm areas, growing on trees and rocks in forests.

[Harufumi Nishida]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

ウラボシ科の常緑性シダ。イワマメ、マメゴケともいう。根茎は細長くはい、鱗片(りんぺん)をまばらにつける。鱗片は格子状で、暗褐色、膜質。葉は肉質で厚くやや光沢があり、栄養葉と胞子葉の2型がある。栄養葉は円形か楕円(だえん)形で長さ1～2センチメートル、柄(え)が短い。胞子葉はへら形で長さ2～5センチメートル、柄が長い。胞子嚢(のう)群は中肋(ちゅうろく)に沿って線状につくが、成熟すると裏面全体を覆う。東北地方南部以西に分布し、暖地に多く、林内の樹上や岩上に着生する。

［西田治文］

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